Fuji Electric Co., Ltd.

Shinichi Hashimoto

Masato Nishizawa

Yoshiyuki Sakai

Yuichi Urano

Naoki Ito

Yoshiyuki Sugahara

A polysilicon film is deposited in a trench formed in a silicon element substrate. The polysilicon film in the trench and on the silicon element substrate is anisotropically etched, so that the film remains on the side wall of the trench. The polysilicon film on the side wall is oxidized to obtain an insulating film, which buries the trench. At the same time, an oxidized film is formed on the surface of the silicon element substrate to complete a trench-mold separation area.

Semiconductor device manufacturing method

Alternate formation of high-resistance and low-resistance layers form a thin film with reduced dopant gradient in its thickness. A desired sheet resistance is attained by adjusting the thickness of the stacked layers, the degree of doping of the film, and the number of layers used to make the thin film during the film formation process.

Method for forming a thin film

A method for separating a joined substrate type wafer, which wafer is composed of a pair of semiconductor substrates joined through an insulation film, utilizes dielectrics through simple processing steps. Trenches for separating a semiconductor substrate with dielectrics are dug from the surface of the substrate and a dielectrics film is deposited on the surface of the substrate including the trenches. Then poly-crystalline silicon is grown by CVD to a thickness of about 0.5 .mu.m, which is deep enough to fill the trenches. The process time for growing poly-crystalline silicon is shortened, and the processing step for removing the poly-crystalline silicon deposited on the unwanted areas is eliminated by growing the poly-crystalline silicon in the trenches but not on the crystalline surface of semiconductor regions based on the growth rate dependence of the poly-crystalline silicon on the crystallinity of the surface on which the poly-crystalline silicon is grown.

Growing community of inventors

Nagano, Japan

Shinichi Hashimoto